Question 900794
Ishaan's age now is {{{ i }}}
Ashley's age now is {{{ a }}}
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(1) {{{ i = a + 9 }}}
(2) {{{ i - 19 = 4*( a - 19 ) }}}
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Substitute (1) into (2)
(2) {{{ a + 9 - 19 = 4*( a - 19 ) }}}
(2) {{{ a - 10 = 4a - 76 }}}
(2) {{{ 3a = 66 }}}
(2) {{{ a = 22 }}}
and
(1) {{{ i = a + 9 }}}
(1) {{{ i = 22 + 9 }}} 
(1) {{{ i = 31 }}}
Ishaan is 31 now
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check:
(2) {{{ i - 19 = 4*( a - 19 ) }}}
(2) {{{ 31 - 19 = 4*( 22 - 19 ) }}}
(2) {{{ 12 = 4*3 }}}
(2) {{{ 12 = 12 }}}
OK